This invention relates in general to signal communication cables and connectors, and in particular, provides apparatus for transmitting signals and electrical power via an integrated assembly of optical fibers and electrical conductors.
Optical fibers are used to transmit signals in a variety of applications, including submarine cables. Signal repeaters and amplifiers are usually Provided at intervals along the length of submarine cables, to compensate for signal attenuation by the cables. Such repeaters require electrical power carried by metallic conductors. In conventional submarine optical cable practice, electrical power is provided to repeaters and other associated submarine electrical devices by separate electrical cables. The plurality of cables thus required increases the complexity and cost of deploying and operating submarine cable, and reduces reliability by increasing the probability of infiltration by seawater under hydrostatic pressure.
A number of optical fiber cable and connector configurations which incorporate metallic conductors have been developed. The following U.S. Patents disclose examples of such cables and connectors:
4,156,104--Mondello PA1 4,239,336--Parfree et al PA1 4,278,835--Jackson PA1 4,371,234--Parfree et al PA1 4,606,604--Soodak
The Mondello patent discloses an optical fiber cable including a core of optical fibers surrounded by stranded steel layers. A metallic tubular jacket surrounds the stranded steel layers to provide a DC path for powering optical repeaters.
The Parfree et al ('336) patent discloses a cable including optical fibers disposed within a tubular electrical conductor.
The Jackson patent discloses an optical fiber cable wherein the optical fibers are disposed within a copper or aluminum tube. The electrically conductive tube allows the transmission of electrical power between repeaters.
The Parfree et al ('234) patent discloses an optical fiber cable having a central strength member over which are laid optical fibers. The fibers are surrounded by a sheath which itself is within an aluminum tube usable to convey electrical power for repeaters.
The Soodak patent discloses a cable including an optical fiber bundle sealed in an electrically conductive metallic tube.
The above patent accordingly describe optical fiber cables and connectors which incorporate a single electrical conductor. However, the prior art cables described in the above patents do not Provide a compact, easily fabricated configuration including an optical fiber core and Plural insulated electrical conductors. A compact optical fiber cable having plural electrical conductors could conduct electrical power and signals to cable-associated electrical devices more efficiently, and with potentially higher reliability, than conventional single-conductor cables. There accordingly exists a need for a compact configuration of optical fibers and Plural electrical conductors suitable for submarine cable applications.
It is accordingly an object of the invention to provide an improved hybrid fiber optic/electrical submarine cable and corresponding connectors.
It is another object of the invention to Provide a compact fiber optic/electrical cable and connector configuration offering low signal attenuation and enhanced resistance to infiltration of seawater under hydrostatic pressure.
It is a further object of the invention to provide a connector for a fiber optic/electrical cable which is compact, robust and easily assembled.
Other general and specific objects of the invention will in part be obvious and will in part appear hereinafter.